CLASS XV. ORDER I.] DRABA. 887 



round, five to many flowered, smooth ; leaves lanceolate, toothed, 

 hairy; petals deeply cloven ; silicula oblong ovate; style very short. 



English Botany, t. 586. English Flora, vol. iii. p. 158. Hooker, 

 .British Flora, ed. 4. vol. i. p. 249. Erophila vulyaris. De Cand. 

 Prod. 1, p. 172. Lindley, Synopsis, p. 26. 



Root small, fibrous. Leaves mostly numerous, radical, lanceolate, 

 acute, somewhat tapering towards the base, more or less toothed or 

 entire, and rough, with simple or forked hairs. Inflorescence an erect 

 round smooth scape, from one to three or four inches long, terminating 

 in a loose raceme of from four to fifteen flowers, the pedicles slender, 

 spreading. Calyx of four ovate concave pieces. Corolla of four 

 spreading white petals, deeply cloven. Stamens with simple awl- 

 shaped filaments and yellow anthers, of two roundish cells. Fruit a 

 smooth ovate oblong or elliptic oblong silicula, with flat rarely some- 

 what swollen valves, smooth, two celled, each cell many seeded, the 

 seeds small, flat, round, the cotyledons accumbent. 



Habitat. Old walls, dry sandy banks, and rocks; frequent. 



Annual; flowering in March and April. 



** Petals entire, or slightly emarginate. 



2. D. aizoi'des, Linn. (Fig. 1024.) Yellow Alpine Whitlow Grass. 

 Scape round, smooth ; petals yellow, as long again as the calyx, 

 slightly notched ; silicula ovate, with a long style; leaves lanceolate, 

 acute, smooth, shining, keeled, the margin ciliated with rigid bristles. 



English Botany, t. 1271. English Flora, vol. iii. p. 158. Hooker, 

 British Flora, ed. 4. vol. i. p. 250. Lindley, Synopsis, p. 26. 



Root of spreading branched fibres. Stems several, repeatedly 

 branched, and tufted. Leaves numerous, crowded at the end of the 

 branches, lanceolate, acute, dark green, smooth and shining, keeled, 

 the margin ciliated with white rigid bristly hairs. Scape erect, from 

 one to two inches long, round, smooth, terminating in a sub-corymbose 

 cluster of bright yellow flowers. Calyx of four equal broadly orate 

 concave pieces, sub-membranous on the margin. Corolla of four 

 ovate obtuse or slightly emarginate petals, with a short claw, as long 

 again as the calyx. Stamens with simple awl shaped filaments and 

 yellow anthers, of two rounded lobes. Fruit an ovate silicula, scat- 

 tered over with hairs, compressed, two celled, each cell containing 

 several roundish pale compressed seeds. Style almost as long as the 

 silicula. 



Habitat. Walls and rocks about Swansea, South Wales. 



Perennial ; flowering in March and April. 



This beautiful little species of Draba is frequent on the rocks in 

 alpine districts of the Continent, where its bright yellow flowers and 

 dark green foliage hanging in matted tufts are extremely ornamental, 

 and it derives nourishment from rocks, where but little seems likely to 

 be obtained ; but it spreads its long slender branched roots amongst 



